Hydrodynamic pressure on gravity dams subjected to ground motions

A new boundary integral equation for the scalar wave equation is developed and applied to obtain the hydrodynamic pressure distributions on dams when the dam-reservoir system is subjected to ground motions. The effect of water compressibility is included in the formulation. The differentiation of the hydrodynamic pressure with respect to time is approximated by functions that satisfy the free surface boundary condition. The wave equations are solved by using the concept of the complementary function and the particular integral, in conjunction with the boundary element method. With this procedure, it is unnecessary to use the fundamental solutions, which are functions of frequency, but only as functions of geometry. As a consequence, the boundary integral equation can be reduced to a classical form that can be solved by using the well-established method. Furthermore, substantial reduction in computing time is achieved. Numerical results based on the proposed procedure are obtained and compared with available analytical and numerical solutions.